s390/bios: build with -fdelete-null-pointer-checks

Starting with version 4.9, GCC assumes it can't safely dereference null
pointers, and uses this for some optimizations. On s390, the lowcore
memory is located at address 0, so this assumption is wrong and breaks
the s390-ccw firmware. Pass -fdelete-null-pointer-checks to avoid that.

Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Alexander Graf <agraf@suse.de>
Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Message-Id: <1434363843-14576-1-git-send-email-aurelien@aurel32.net>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Aurelien Jarno 2015-06-15 12:24:03 +02:00 committed by Christian Borntraeger
parent 795dc6e46d
commit 8369e339d2

View File

@ -10,7 +10,7 @@ $(call set-vpath, $(SRC_PATH)/pc-bios/s390-ccw)
.PHONY : all clean build-all
OBJECTS = start.o main.o bootmap.o sclp-ascii.o virtio.o
CFLAGS += -fPIE -fno-stack-protector -ffreestanding
CFLAGS += -fPIE -fno-stack-protector -ffreestanding -fno-delete-null-pointer-checks
LDFLAGS += -Wl,-pie -nostdlib
build-all: s390-ccw.img